Yukiko Takashiro (submitted name) is someone who has long struggled with her innate masochistic desires since childhood. For six years, she underwent strict training under a dominant master she met in college, a period that profoundly shaped her life. However, due to family circumstances and her master's overseas transfer, they were forced to part ways. Returning to her hometown, she concealed her masochistic tendencies, got married, and briefly lived a seemingly happy life. Yet her submissive nature never left her, eventually dragging her back into its grasp. By chance, her former master returned to Japan and moved into an apartment near her home. Their reunion after six years reignited her deep-rooted masochism. Despite overwhelming guilt, she has become consumed by the pleasures of submission and is now being lent out as a living sex slave, openly exposing her depraved acts to numerous men as she strives to achieve penetration by 500 different cocks. This release features raw footage shot by amateur BDSM enthusiasts, devoid of the scripted performances, staged scenes, or narrative elements typical of commercial adult videos—instead offering a brutally honest and intensely lewd viewing experience.